1. Field of the Invention
The invention relates to an insulated wire and a cable.
2. Description of the Related Art
Insulated wires used in rolling stocks, automobiles and electrical equipment, etc., could be involved in a fire accident or could be worn out by, e.g., contact with another member or rubbing against other insulated wires. Thus, insulated wires are required to have flame retardancy or abrasion resistance to stably function under such conditions.
For example, use of a polymer excellent in flame retardancy such as polyvinyl chloride as a material of the insulation layer and addition of a halogen-based flame retardant to the material of the insulation layer are known as the methods of improving flame retardancy of insulation layer. However, in recent years, halogen-free materials not containing halogen have been used in view of safety in the event of fire or in view of reduction of environmental burdens.
For example, resin compositions in which a halogen-free flame retardant such as metal hydroxide is mixed to polyolefin are known as the halogen-free materials (see, e.g., JP-A 2013-18932).
These resin compositions are generally highly cross-linked to improve mechanical characteristics, such as cut-through properties or abrasion resistance, of the insulation layer.